When performing a wet etching processing or a cleaning processing on a substrate such as, for example, a semiconductor wafer, a single type substrate processing apparatus is frequently used. The single type substrate processing apparatus includes a spin chuck configured to hold a substrate horizontally and rotate the substrate around a vertical axis, and a nozzle configured to supply a processing liquid to a top surface of the rotating substrate. In many cases, the nozzle is attached to a movable arm to be movable between a processing position just above the substrate and a standby position located outside the substrate. When located at the processing position, the nozzle ejects the processing liquid vertically downwardly.
In addition to or instead of the vertically downward ejection type nozzle, a nozzle may be provided in some cases in a type of ejecting a processing liquid transversely (substantially horizontally) toward the central portion of the top surface of the substrate from the outside of the substrate (see, e.g., Japanese Patent Laid-Open Publication No. 2013-093361). The transversal ejection type nozzle may be usually fixed to a position radially outside the substrate (e.g., to the top surface of a cup), and used for forming a liquid film on the top surface of the substrate in order to prevent the top surface of the substrate from coming in contact with the air, for example, between a substrate processing by a first processing liquid and a substrate processing by a second processing liquid.
The fixed transversal ejection type nozzle has a drawback in that it cannot perform a dummy dispense. This is because when the dummy dispense is performed, a liquid, which may contaminate the spin or the spin chuck, comes in contact with the substrate or the spin chuck. In addition, when the liquid ejected from the nozzle drops onto a constituent member of the substrate liquid processing apparatus below the nozzle (e.g., the top surface of the cup), the constituent member itself may be contaminated. In addition, the liquid splashed from the constituent member may contaminate a member around the constituent member.